Frequently asked questions about malaria
- What is malaria?
- What are the different types of malaria?
- How is malaria transmitted?
- Who is most at risk of getting very sick and dying from malaria?
- How is malaria treated?
- How is malaria controlled?
Malaria is a parasitic infection transmitted to humans through the bites of infected female Anopheles mosquitoes. The resulting disease in humans can be devastating. After moving rapidly to the liver, the parasite moves into the blood stream to settle in the red blood cells, where it multiplies and emerges in bursts of new organisms. These parasites, because of their large numbers, can cause particular damage to the nervous system, liver, and kidneys.
In young children and adults who have not recently been infected (and therefore have not developed natural immunity), this cycle can result in death within hours from cerebral malaria. Others also die from overwhelming anemia or liver and kidney failure. Malaria is a leading cause of death and illness in developing countries, hitting hardest in resource-poor tropical and subtropical areas. Malaria transmission, which is affected by climate and geography, often coincides with the rainy season. The disease kills hundreds of thousands of people annually, most of them sub-Saharan African children under age five.
Malaria parasites known to infect humans include:
- Plasmodium falciparum
- Plasmodium vivax
- Plasmodium malariae
- Plasmodium ovale
- Plasmodium knowelsi
Among the species of the malaria protozoan parasite, Plasmodium falciparum is the deadliest.
Malaria is transmitted by the female Anopheles mosquito, of which there are more than 40 species. When a mosquito bites an infected person, it takes in a small amount of blood, which contains microscopic malaria parasites. About one week later, when the mosquito takes its next blood meal, these parasites mix with the mosquito’s saliva and are injected into the person being bitten. Malaria may also be transmitted from a mother to her unborn infant before or during delivery.
Every year, P. falciparum malaria causes the deaths of hundreds of thousands of people, most of them sub-Saharan African infants and children. Malaria also contributes to anemia in children and pregnant women, low birthweight, premature birth, and neurological damage. Hundreds of millions of cases of malaria occur every year. In 2010, an estimated 3.3 billion people were at risk of contracting the disease.
Malaria can be treated with a regimen of antimalarial drugs based on the type of infection and status of the patient.
Malaria-control strategies include the use of medicines, insecticides, and insecticide-treated screens and bednets. Control programs led to the elimination of malaria from Australia, Europe, and the United States by the 1950s.